For my 2c, I would definitely look at the Lightspeed Zulu - they are light, the noise cancelling is on a par with the Bose A20 and significantly cheaper but what settled it for me was the Bluetooth streaming of music - on longer distance flights, having music streaming in the background breaks the monotony. You can set it either that it lowers the volume when radio traffic is received and raises again once the airwaves are silent (which, if it's a busy frequency can mean you never hear the music) or just set it at a low background level. Makes flying alone more of a treat. Also, the set comes with a wired music input, should you not have a bluetooth phone but want to use a regular iPod etc.
Also, when choosing your headset, check the sound quality you are receiving. I had a Peltor headset and found myself repeatedly saying "say again" when ATC / FIS called me - with the Zulu, everything is crystal clear.... Oh yeah, the sound quality of music reproduction in the Zulu, especially with their FRC function, just has to be seen to be believed.